The MOMO-2 rocket, developed by Japan’s Interstellar Technology, has exploded four seconds after its lift-off from Hokkaido in Japan.

The rocket burst into flames, causing damage to some parts of the launch pad.

MOMO-2 is the company’s second rocket, and would have been Japan’s first privately developed rocket to reach outer space.

The unmanned rocket weighs 1t and is 10m in length and 50cm in diameter. It featured equipment developed by Kochi University of Technology to measure how soundwaves propagate at high altitude.

MOMO-2 was originally planned to be launched in late April, but a nitrogen leak found in the rocket delayed the launch.

“We could not accomplish what we were expected to do. I feel sorry for that.”

The latest incident is the second failure for Interstellar Technologies, which tried to get its MOMO-1 rocket to an altitude of more than 100km last July but had to abort after losing contact some 70 seconds into the flight.

Interstellar Technologies president Takahiro Inagawa told japantimes.co.jp: “I could not immediately understand what happened.

“We could not accomplish what we were expected to do. I feel sorry for that.”

Inagawa added that MOMO-2’s main engine might have encountered a problem that led to its crash.

Interstellar has raised nearly $257,000 through crowdfunding to fund the launch.

Interstellar Technologies founder Takafumi Horie said: “We have to find ways to improve.”

The company, however, has not decided anything about its next launch.